磁刚度公式获得： 电子做圆周运动，r即p x=rsine,y=rcos0,0=ot=-t =vcos dy dt d C a, t,a,= dv, -cos dt dt a=Va+a=→F=ma= r 此力为电子在二极铁垂直磁场B中运动的洛仑兹力 F=gevB eB gevB= 35 35 sin , cos , v x r y r t t r = = = =     cos , sin x y dx v dy v v v t v v t dt r dt r     = = = = −         2 2 sin , cos x y x y dv v c v v dv a t a t dt r r dt r r     = = − = =         电子做圆周运动，r即ρ 2 2 2 2 x y v mv a a a F ma r r = + =  = =F qevB = 此力为电子在二极铁垂直磁场B中运动的洛仑兹力 2 mv qevB r = 1 qeB G  P = = x y θ r ρ 磁刚度公式获得: